Arrangement for machining and/or assembling components

ABSTRACT

An arrangement comprises several work stations for machining and/or assembling components. Receivers for holding components are provided on workpiece holders (3) connected to a feed drive in the form of a conveyor chain (5). Guide devices with guide tracks (11, 12) for the conveyor chain are arranged in identical housing parts (8). The guide tracks (11, 12) are of equal length. The housing parts (8) are connected to one another and to a reversing station (7) for the conveyor chain (5) by means of guide and/or coupling devices (10) to form a housing unit supported on a contact surface (14) by supporting devices (13).

The invention relates to an installation for processing and/orassembling components, having workpiece carriers, which are providedwith receptacles for holding components, and, connected thereto, a chainconveyor as a feed drive and having a guidance device disposed inhousing parts with guideways for the chain conveyor.

In installations of this type, a basic distinction can be made betweenso-called loosely concatenated and rigidly concatenated installations.In loosely concatenated installations, the workpiece carriers are movedalong the installation completely independently of one another and, inthe event that a device in a single workstation breaks down, for aspecific period of time this has virtually no effect on the activity ofthe other workstations. In rigidly concatenated installations, theworkpiece carriers are interconnected in their movement so that, iffaults arise in the vicinity of one workstation, all the workpiececarriers and all the workstations are blocked. Each of the two types ofinstallation has its own range of application, the rigidly concatenatedinstallations being used where only a few workstations are concatenatedsince the total utilisation rate is a product of the utilisation ratesof the individual workstations. Loosely concatenated installations aregenerally used to concatenate a plurality of workstations, e.g. up to 40or more, since in this case the utilisation rate is then a valuecompounded from the individual occurrences of faults rather than theproduct of the utilisation rates in the individual stations.

Many different installations with loose concatenation are alreadyknown--e.g. from DE-OS 35 02 868, DE-OS 35 02 820, DE-OS 34 11 452,DE-OS 33 04 091 and DE-PS 27 56 422 of the same applicant--which haveproved successful in practice for concatenating a plurality ofworkstations. The workpiece carriers are in each case conveyed alonglateral and vertical guideways independently of one another, andappropriate use of conveying rollers pressed against the side surfacesof the workpiece carriers ensures lateral and vertical guidance of theworkpiece carriers without any play. Thus, accurate positioning of theworkpiece carriers is achieved throughout the entire course of such aninstallation in cooperation with the drive means.

Rigidly concatenated installations are also known--from DE-OS 26 40593--in which the individual workpiece carriers are connected by chainconveyors. Up till now, it has been difficult to series-produce suchinstallations or to make them adaptable to varying requirements with avarying number of workstations. It was moreover difficult to install thechain on the assembly or processing devices disposed in theworkstations. The further known rigidly concatenated installations forprocessing and assembling components are formed by rotary tables whichmay possibly also be concatenated by way of additional conveyingdevices--e.g. according to DE-OS 31 34 195. Such rigidly concatenatedinstallations, which may be formed by rotary tables, cannot subsequentlybe extended by adding extra workstations and take up a great deal ofroom, especially when a plurality of workstations are arranged intandem. Furthermore, access, assembly and maintenance are made verydifficult by the compact arrangement of the assembly and handlingdevices or processing devices disposed inside the rotary table.

The aim of the present invention is to provide an installation forprocessing and/or assembling components which is of a simple andwell-arranged construction, can easily be adapted to a varying number ofworkstations and can subsequently be extended at any time. Furthermore,there should be precision guidance of the workpiece carriers in such arigidly concatenated installation.

The aim of the invention is achieved in that the housing parts are ofidentical construction and preferably one length of the guideway of saidparts is of an identical size, and in that the housing parts areconnected to one another and to a chain-guiding station for the chainconveyor by way of guidance and coupling devices to form a housing unit,said devices being supported by means of support devices on a supportsurface. The advantageous effect achieved by this seemingly surprisingsimple combination of features is that even a rigidly concatenatedsystem of relatively simple construction may quickly be adapted todiffering requirements since it may be adapted for any number ofworkstations by adding further housing parts. Furthermore, since thehousing parts are identical in construction, the installation may alsohave additional housing parts added on at any later stage. It ismoreover also possible to series produce the individual components ofsuch an installation on a commercial basis, with the result that theymay be interchanged at random and can be produced inexpensively. Thisallows such installations to be used also in fields where up till nowautomated assembly and processing of workpieces has seemed impossibleowing to the high cost of such an installation.

According to a further embodiment, it is provided that the housing partsare of identical dimensions, thereby permitting the housing parts to beinterchanged at random.

It is however also advantageous if the housing parts between thechain-guiding stations are disposed in a self-supporting manner as thisallows the weight and the outlay for manufacturing such an installationto be additionally reduced.

It is also possible for a continuous fastening device, e.g. an assemblyrail, by means of which the support devices and supply devices and othermeans cooperating with the workpiece carriers may easily be positioned,to be disposed on the housing parts along the guideway.

It is, however, also possible for the housing part, which is inparticular constructed as a single piece, to be of a cantilever designand to carry two parallel-running guideways for a drawn and a returncourse of the chain of the chain conveyor. It is thereby possible tofind installations with only one housing part for guidance of the chainconveyor.

According to another design variation, it is provided that the guidewaysare interconnected by way of end plates which carry the guidance andcoupling devices, thereby achieving a compact, torsion-proof componentas a housing part which without additional measures also has cantileverproperties.

A further alternative, however, is for the guideway on the housing partto comprise guide rails extending parallel to an upper side of saidguideway for vertically guiding workpiece carriers forming the chainlinks of the chain conveyor. This makes it possible to achieve exact andprecise guidance of the workpiece carriers in the individual work areasindependently of any sagging or swinging of the chain conveyor. By usingindividual guide rails, a high degree of guiding precision may beachieved independently of the material of the housing part.

It is however also advantageous if the guidance device comprises alateral guideway for the chain links or workpiece carriers of the chainconveyor, said lateral guideway extending parallel to the guidewaydisposed on the upper side of the housing part, as this allows theindividual chain links to be guided and positioned precisely relative tothe housing part completely independently of their hingedinterconnection. Thus, the chain links may be used directly as workpiececarriers and it is possible to dispense with an additional centering ofthe individual workpiece carriers in the workstations.

Furthermore, it is also possible for the lateral guideway to be formedby support rollers which are arranged spaced apart from one anotheralong the guideway and are supported on axes extending approximately atright angles to the upper side of the housing parts, this allowing theguidance precision to be maintained even over an extended operatingperiod.

According to another variation, it is provided that the support rollersare disposed on either side of the chain conveyor, thereby achievingcentral guidance of the chain links.

A construction is also advantageous wherein the support rollers areassociated with one longitudinal side of the chain conveyor and apressure device for exerting a pressure force directed towards thesupport rollers--arrow 32--is associated with the opposite longitudinalside. This achieves precise guidance along a lateral guideway lyingopposite the pressure device independently of the precision of the guidesurfaces or the arrangement of the support rollers. What is more, thepressure device additionally damps the running of the chain conveyor asa result of restraint and prevents the chain conveyor from jumping orknocking as it moves forward from one workstation to another.

According to another embodiment, it is provided that a table board foraccommodating handling and/or processing devices is supported so as tobe movable relative to the housing parts, this achieving in asurprisingly simple manner the effect that, after tensioning of thechain conveyor, the assembly and/or processing devices disposed on thetable boards may be adjusted to the position of the workpiece carriersor chain links. Thus, the amount of work required to align the assemblyand/or processing devices in the individual workstations isadvantageously reduced and also, when regulating the tension of thechain, the amount of work required and hence maintenance costs are alsolow.

It is moreover also possible for a clearance to be disposed between theguideways and the end plates, thereby achieving a profile-likeconstruction for the housing part and hence a high rigidity.

It is however also possible for the table board to be disposed in theclearance and for one length of the table board to be smaller than alength of the clearance longitudinally of the guideways, therebyallowing this clearance to be used preferentially for disposition of thetable board and advantageously allowing support facilities for the tableboard to be disposed in this clearance.

However, it is also advantageous if support rails for the table boardare disposed in the clearance since all that is then necessary is anadjustment of the table board or the workpiece carriers to position thehandling and/or processing devices relative to the chain conveyor.

According to another variation, it is provided that a guide sprocket forthe chain conveyor is disposed in the chain guiding stations and a feeddrive for the guide sprocket is associated with at least one of twochain guiding stations associated with the housing units, thereby alsoallowing the parts for chain guiding of the chain conveyor to bemanufactured in greater quantities and in series production and to beinterchangeable. Furthermore, only one design principle is required forthe driven and the following chain guiding station.

It is also advantageous if the guide sprocket is connected to a dampingand/or setting device, e.g. a threaded spindle or a spring arrangement,extending longitudinally of the chain conveyor since by these means theshocks occurring during startup of the chain conveyor are damped and itis possible to achieve continuous adjustment, as the chain conveyorbecomes worn at the hinged points, by maintaining a pre-defined tension.

It is also advantageous if a spring-locking device is associated withthe damping device for the guide sprocket as this allows the tensioningof the chain and the damping of shocks acting upon the chain to beadvantageously combined.

It is however also possible for both guide sprockets to be coupled to afeed drive and for a damping and/or setting device and a spring-lockingdevice to be associated with each of these feed drives since, when usingtwo chain guiding stations which are fitted with feed drives, it ispossible to feed the chain conveyor in alternate directions.

According to another embodiment, it is provided that the verticalguideway in the chain guiding station extends from the housing partdisposed directly upstream thereof as far as over a drive shaft or theguide sprocket. As a result, the differing chain speeds and changes inthe length of the chain conveyor arising from the polygonal effect canbe compensated.

It is further possible for a distance between the vertical guideway andthe axis of rotation or drive shaft in the region of the zenith of theguide sprocket to be greater than a radius of a root circle of the guidesprocket and for this distance to decrease in a peripheral direction ofthe guide sprocket to this radius. Owing to the design of the verticalguideway, the chain links of the chain conveyor only mesh at the end ofthe vertical guideway in the region of the root diameter of the guidesprocket, with the result that the chain links or workpiece carriers canbe conveyed horizontally and supported without play also in the regionof the vertical guideway of the housing part disposed directly upstreamof the chain guiding station.

It is further advantageous if the vertical guideway in the chain guidingstation comprises a guide rail part which may be positioned my means ofa longitudinal setting device, e.g. clamping blocks which aredisplaceable on a guide column, as this makes it possible continuouslyto readjust the guidance of the chain links in this transition regionbetween housing part and chain guiding station also during tensioning ofthe chain conveyor and in the event of changes in length duringoperation.

A construction is also advantageous wherein the vertical guideway in thechain guiding station comprises two guide rail parts which aretelescopically displaceable relative to one another as this permits ajerk-free passage of the chain links in the adjustment region.

An embodiment is also advantageous wherein the chain conveyor isprovided with track rollers, which are associated with the guideways andare spaced apart from one another at right angles to the chainlongitudinal direction, and wherein one width of the guide rail parts issmaller than a width of a track roller which meshes in the guidesprocket with the result that sliding friction is avoided both in theregion of the guideway and in the region of the guide sprocket.

It is however also possible for one length of a housing part to be amultiple of a width thereof, thereby allowing access to the chainconveyor and requiring only a short stroke for handling devices used,for example, to supply parts from the supply devices to the workpiececarriers.

It is further possible for one length of a housing part to correspondroughly to a length of three chain links, thereby also allowing aplurality of workstations to be disposed in tandem over the length of ahousing part.

It is however also advantageous if the chain links form the workpiececarriers since it is then possible to keep the masses moved in theinstallation to a minimum.

According to another variation, it is provided that the support deviceis formed by L-shaped supports which are disposed at side surfaces ofthe housing parts or chain guiding station and have two legs of unequallength, of which the shorter is associated with the contact surface andthe longer is associated with the housing part or chain guiding station,and that preferably in the same cross-sectional area a support isdisposed on each of the opposing side faces in a mirror-inverted manner,with the result that the space required for support of the installationis kept low and ease of access to the individual parts of theinstallation is achieved.

It is however also advantageous if the pressure device is formed byradially resilient pressure rollers and a distance between an unstressedpressure roller and the opposing lateral guideway is smaller than awidth of the chain conveyor or the workpiece carriers coupled thereto,with the result that during the entire movement of the chain conveyorbetween the pressure rollers and the lateral guideway play-free andjerk-free guidance of the chain conveyor is guaranteed.

It is also possible for the pressure rollers and support rollers to bedisposed offset relative to one another in the feed direction of thechain conveyor, thereby excluding the possibility of the workpiececarriers or chain links being flung transversely relative to their feeddirection.

According to another advantageous development, it is provided that thepressure rollers and/or the support rollers are coupled to a drivemechanism, e.g. a drive motor or a chain or belt drive, because it isthen possible, even when disposing additional housing parts in anexisting installation, to get by without changing the required power ofthe feed drive in the chain guiding station since some or all of thepressure rollers may be additionally provided with a drive mechanism. Atthe same time, it is thereby possible to ensure specific accelerationand deceleration values by providing the pressure rollers with their owndrive in addition to the drive of the chain conveyor.

It is moreover advantageous if the feed drive is a servo drive, e.g. anelectric stepping motor, because then the workpiece carriers or chainlinks can be positioned in the individual work areas by means of thefeed drive.

For a clearer understanding of the invention, it is describedhereinafter in greater detail with reference to the embodimentsillustrated in the drawings:

These show:

FIG. 1 a simplified diagrammatical side view of an installationaccording to the invention;

FIG. 2 a front view, in section along the lines II--II of FIG. 1, of theinstallation;

FIG. 3 a diagrammatical, extremely simplified view of a housing part ofthe installation according to the invention with the chain conveyor andthe lateral and vertical guideways and the table board;

FIG. 4 a front view, in section, of the workpiece carrier of FIG. 3 withthe lateral and vertical guideways of the housing part which areassociated with it;

FIG. 5 a side view of a housing part as in FIGS. 1 to 3;

FIG. 6 a side view, in section along the line VI--VI of FIG. 7, of atransition region between a housing part and a chain guiding station;

FIG. 7 a plan view of the transition region between the housing part andthe chain guiding station of FIG. 6;

FIG. 8 a front view, in section along the line VIII--VIII of FIG. 6, ofthe chain guiding station;

FIG. 9 a side view of part of a chain conveyor constructed according tothe invention and comprising a chain link;

FIG. 10 a plan view of the workpiece carrier of FIG. 9.

FIG. 1 shows an installation 1 for processing and/or assemblingcomponents 2. These components 2 are disposed on workpiece carriers 3.For holding the components 2 on the workpiece carriers 3, receptacles 4are connected to the workpiece carrier 3 or are moulded as a singlepiece thereon. The workpiece carriers 3 in the present embodiment form achain conveyor 5. A feed drive 6 which is disposed in the region of achain guiding station 7 for the chain conveyor 5 is used to advance thechain conveyor 5. Located between the two chain guiding stations 7 are aplurality of housing parts 8 which, in the illustrated embodiment, areself-supporting. These housing parts 8 have end plates 9 which face oneanother and may be interconnected by means of guidance and couplingdevices 10 to form a self-supporting housing unit. Guideways 11, 12extend at right angles to the end plates 9, with the drawn course of thechain conveyor 5 being conveyed in the guideway 11 and the return coursebeing conveyed in the guideway 12. By way of the guidance and couplingdevices 10 between the individual housing parts 8, the strung-togetherguideways 11 and 12 of the housing parts 8 form a continuous planeguidance device for the chain conveyor 5. The installation 1 formed bythe housing parts 8 and the chain guiding stations 7 is supported bysupport devices 13 on a support surface 14.

The support devices 13 are formed by L-shaped supports which aredisposed in a mirror-inverted manner relative to a vertical plane ofsymmetry 15 and are connected to the housing parts 8 in the region ofside walls 16. To facilitate fastening of the L-shaped supports to theside walls 16, longitudinally extending assembly rails 17 forming acontinuous fastening device are provided. These assembly rails 17 areformed, for example, by T-shaped grooves into which are inserted slidingblocks 18 whose sectional shape is adapted to the groove shape and whichare provided, for example, with a thread of their ends facing thesupport devices 13, with the support devices 13 being pressed againstthe side walls 16 of the housing parts 8 and fixed in relation theretoby means of nuts. One advantage to be derived from use of such acontinuous fastening device is that the support devices 13 may bepositioned at any point along the installation 1 so as not to obstructthe arrangement of workstations or of handling or supply unitsassociated therewith. Similarly, these continuous fastening devices mayalternatively be used to fix the end positions of supply units orhandling devices so that they may be utilised in numerous ways.

As FIGS. 1 and 2 show, the housing parts 8 are of uniform dimensions,having a length 19, a height 20 and a width 21. Thus, the housing parts8 may easily be assembled in a streamlined manner and individual housingparts 8 can be interchanged without difficulty. The continuous fasteningdevice in the form of assembly rail 17 also makes it possible, wheninterchanging individual housing parts 8, for the housing parts 8 whichare directly adjacent to be provisionally supported by means of supportdevices 13 with the result that, for example, a defective housing part 8or the workstation disposed in the region thereof can easily be replacedby a workstation of a different type.

With a suitably designed fastening device, especially with precisionconstruction of the longitudinal alignment of this fastening device, itis also possible by inserting sliding pads in the transition regionbetween adjacent housing parts 8 to position these two housing parts bymeans of this sliding pad both vertically and laterally and to fix themin position. Designing the guidance and coupling device 10 in this waywould make it possible for the individual housing parts 8 to be removedand installed at right angles to a feed direction--arrow 22.

As is further shown, the support devices 13 may be fitted with feetelements which are adjustable perpendicular to the support surface 14 sothat the installation may be erected horizontally irrespective of unevenareas in the region of the support surface 14.

FIG. 3 shows a housing part 8. The guideway 11 carries the drawn courseof the chain conveyor 5 and comprises guide rails 23 for verticalguidance of the chain links forming the workpiece carriers 3. Lateralguideways 24, 25, which are formed by support rollers 28 and pressurerollers 29 disposed one behind the other at a distance 26 and 27 in feeddirection--arrow 22, are used for lateral guidance. The support rollers28 are associated with a side surface 30 of the workpiece carrier 3 andthe pressure rollers 29 are associated with a side surface 31 lyingopposite said side surface 30. The pressure rollers 29 exert a pressureforce, indicated by arrow 32, upon the workpiece carriers 3 in thedirection of the support rollers 28. As a result, the workpiece carriers3 take up a precise position, which is accurate to a fraction of amillimeter, at right angles to the direction of progressive movementindicated by arrow 22. Precise vertical guidance is meantime ensured bythe guide rails 23.

To permit accurate vertical and lateral guidance of the workpiececarriers 3 over an extended period of time, said workpiece carriers aresupported on the guide rails 23 by means of track rollers 33. Thesetrack rollers 33 are supported on an axis serving as a chain link pin34. The chain link pin 34 in each case connects two successive workpiececarriers 3, which form the chain links, for joint progressive movementin a direction at right angles to the guide rails 23, i.e. verticallyand in feed direction--as per arrow 22--i.e. longitudinally and in thedirection of conveying. Vertical guidance of the workpiece carrier 3 istherefore effected in each case by the track rollers 33 and by the trackrollers 33 associated with the workpiece carrier located directlyupstream, with the workpiece carrier 3 in each case being supported bythe chain link pin 34 on these track rollers 33. In order to allowindependent lateral positioning for each workpiece carrier 3, a width 35of a recess 36 in the workpiece carrier 3 is greater than a width 37 ofa coupling extension 38 carried on the chain link pin 34. This enablesthe chain links or workpiece carriers 3 directly succeeding one anotherto be adjusted laterally relative to one another, with the lateraladjustment of the workpiece carriers 3 then being influenced only by theposition of the lateral guideway 25 and not by the position of the chainconveyor 5 as such.

As FIG. 3 further shows, the housing part 8 is constructed as a singlepiece and, besides the guideway 11, also has on its lower side aguideway 12 formed by guide rails 39 in which the return course of thechain conveyor 5 is conveyed by means of the track rollers 33. Verticalguide surfaces 40 in the region of said guide rails 39 are used forlateral guidance of the workpiece carriers 3. Said guide surfaces serveto prevent the workpiece carriers from pitching. The two partsaccommodating the guideways 11 and 12 are interconnected by the endplates 9. Disposed in said end plate 9 are alignment pins 41 and bores42 for screws 43 which jointly form the guidance and coupling device 10.Also shown is the continuous fastening device in the form of assemblyrail 17 having a T-shaped cross-section. Instead of the alignment pins41, it is possible to use a coupling rail 44 guided in a mirror-freemanner in the assembly rail 17 for connecting the housing parts 8 on thesame level. If this coupling rail 44 is provided with bores 45, adjacenthousing parts 8 may then be coupled by means of the bores 45 and screwsinserted therein.

A clearance 46, in which a table board 47 is disposed, is defined by theguideways 11, 12 and the end plates 9.

Length 48 of the table board 47 is shorter than a length 49 of theclearance 46. Thus, it is to a limited extent possible to move the tableboard 47 in feed direction--arrow 22--relative to the housing part 8 andto position it. As is diagrammatically illustrated, guidance andfastening of the table board 47 may be effected by means of retainingstraps 50 which are suspended in the assembly rail 17.

As FIG. 3 further shows, disposed between the guide rails 23 is anopening 51 inside which access to the workpiece carriers 3 from below ispermitted. It is therefore possible to provide additional supports forthe workpiece carrier 3, especially in stations where removal of theload of the track rollers 33 of the workpiece carrier 3 is requiredwhile parts are assembled, riveted or pressed in, or it is also possibleto provide rotatable parts in the workpiece carrier 3 which may be setin individual stations into varying rotated position by means of drivemechanisms which act from below on the workpiece carrier 3.

FIG. 4 shows the arrangement of the chain link pin 34 and its bearing inthe coupling extension 38 of the workpiece carrier 3. The chain link pin34 is supported in the coupling extension 38 in a bearing 52, inparticular in a roller or needle bearing. In a bore 53, it penetratesthe side surface 30 of the workpiece carrier 3. Disposed in front of theend of the chain link pin 34 in the region of the side surface 31 is alateral guide rail 54 which prevents the chain link pin from moving atright angles to the feed direction. This lateral guide rail 54, whichmay comprise for example a hardened or nitride metal strip, serves as alocating means for the support rollers 28 which are rotatable aboutvertical axes 55 which are in turn supported or fastened in the housingpart 8. In the region of the opposite side surface 31, the chain linkpin 34 is carried in a blind hole 56. Further bores 57 in the workpiececarrier 3 are constructed as a press fit for receiving and retaining thechain link pin 34. Two track rollers 33 are disposed next to one anotherbetween said bores 57 and the blind hole 56, and between the bore 57 andthe bore 53. These track rollers 33 are similarly formed by rollerbearings. Because of the selected construction, it is therefore easilypossible to operate the chain conveyor 5 in an almost play-free mannerand without wear over an extended period since guidance of the workpiececarrier 3 relative to the guide rails 23 is effected in the form ofrolling friction by the track rollers 33 rolling off on the guide rails23. Similarly, the movements between directly successive workpiececarriers 3, particularly in the region of the chain guiding station 7,are effected by means of the bearing 52 with the result that, in thisregion too, rolling friction but not sliding friction can occur.Naturally it is possible to use sliding bearings instead of the rollerbearings shown, or on the other hand it is also possible to prevent thechain link pin 34 from twisting in the individual bearings 52 or bore 53by means other than the bores 57 designed as a press fit.

As FIG. 4 further shows, the side surface 31 is constructed so as toextend obliquely relative to the plane of symmetry 15. The distance ofthis side surface 31 from the vertical plane of symmetry decreases asthe distance from the guide rails 23 increases. Similarly, the pressurerollers 29 associated with the side surface 31 are designed so as totaper towards the housing part 8. The pressure rollers 29 are rotatablysupported similarly by means of vertical axes 55 which are fastened inthe housing part 8. As the broken lines indicate, said axes 55 of thepressure rollers 29 may also be coupled to a drive motor 58 whichsupports the feed movement of the feed drive 6.

To allow play-free guidance of the workpiece carriers 3 along thelateral guideway 25 formed by the support rollers 28, a distance 59between the axes 55 of the pressure rollers 29 and the support rollers28 is smaller than a width 60 of the workpiece carrier 3 plus a radiusof the support roller 28 and a radius 61 of the radially resilientpressure roller 29. The radially resiliently deformable pressure roller29 exerts a pressure force which extends in the direction of the arrow32 towards the support rollers 28 and by mans of which play-freelocation of the workpiece carrier 3 on the support rollers 28 isachieved. At the same time, as a result of the conical design of thepressure rollers 29, a pressure force is also exerted in the directionof the guide rails 23 and results in the workpiece carrier 3 beingsupported in a play-free manner on said guide rails 23. The end effectis that, despite the workpiece carrier being designed as a chain link,it is possible for it to be guided in a play-free manner along thelateral guideway 25.

As FIG. 4 further shows, the assembly rail 17 allows one end of a linearconveying track 62 of a supply unit to be precisely set in its positionrelative to the housing part 8 with the result that, in the event ofremoval of parts 63, said parts may be picked up by a diagrammaticallyshown gripper 64 always precisely at the correct location and moved fordeposit on the workpiece carrier 3.

Supporting the linear conveying track 62 in this manner by means of asupporting yoke 65 in the assembly rail 17 makes it possible to positionthe linear conveying track both vertically and in a direction at rightangles to the direction of progressive movement and, of course, also inthe direction of progressive movement.

FIG. 5 is a side view of a housing part 8 from which it may be seen thatthe length 19 of the housing part 8 corresponds to a multiple of a chainlink length 66, in the present case three times such a chain link length66. Naturally, it is also possible for the length 19 of the housing partto be only twice a chain link length 66. This achieves the advantageouseffect that any number of housing parts 8 may be strung together becausethe length of the chain can always be extended by precisely three chainlinks or two chain links. If, on the other hand, the chain link length66 is not a whole fraction of the length 19 of the housing part 8, thenwhen extending the installation 1 it is necessary always to consider therequired chain pitch and to compensate the resultant distance by meansof a suitable adjusting path both in the drawn and in the return courseof the chain in the region of the chain guiding station 7.

The table board 47 is supported in the clearance 46 on support rails 67fastened to the end plates 9. Since the length 49 of the clearance 46 isgreater than the length 48 of the table board 47, the table board 47 canbe adjusted in feed direction--arrow 22--relative to the housing part 8.A handling unit 68 and, for example, a screw device 69 is fastened onthis table board 47. Once the chain conveyor 5 has been assembled andtensioned, the working positions resulting from the timed feed of theworkpiece carriers 3 are fixed by the chain conveyor 5. Since theposition of the chain links after each feed movement is howeverdependent upon the span distance and several external factors of theinstallation 1, after the chain conveyor 5 has been completed andassembled it is necessary to adjust the handling units 68 and the screwdevice 69 and other operating equipment to the position of the chainlinks. For this it was previously necessary to position the individualhandling units or screw devices and other operating equipment one by oneon the table boards and move them into a position of alignment withtheir working position on the workpiece carrier 3. Now, however, owingto the arrangement and design of the table board 47 as shown in FIG. 5,it is possible to displace the units or devices arranged in the precisepitch dimension 70 all at once with the table board 47 in feeddirection--arrow 22--or counter to the feed direction, thereby allowingan alignment with the workpiece carriers 3. Thus, by adjusting the tableboard 47 relative to the housing part 8, all the units and devicesdisposed thereon may be set at their exact working position on theworkpiece carrier. This has the advantage that, when the tension of thechain is regulated or a chain link exchanged because of a defect or thelike, the installation can rapidly be restored to a state of readinessfor operation and precise functioning.

FIG. 6 shows the installation 1 in the transition region between a chainguiding station 7 and a directly adjacent housing part 8. The chainguiding station 7 comprises a guide sprocket 71 in the form of a chainwheel which is supported on a drive shaft 72. The drive shaft 72 isdisposed in a housing 73 which is supported on guide columns 74 so as tobe displaceable in feed direction--arrow 22. A threaded spindle 75 whichcan be set in rotation by means of a regulating motor 76 is disposed fordisplacement of the housing 73. The threaded spindle is displaceable bymeans of a travelling nut 77, which is supported in a torsion-proofmanner relative to the housing 73, with a spring arrangement 78interposed in or counter to the direction of the arrow 22. This enablesthe chain conveyor 5, which is formed by the workpiece carriers 3forming the chain links, to be tensioned to an adequate extent. If theguide sprocket 71 is used merely to guide and not to drive the chainconveyor 5, then any impacts or shocks can be compensated by the springarrangement 78. If, on the other hand, the chain conveyor 5 is driven bythe drive shaft 72 and the guide sprocket 71, spring arrangement 78 maybe disengaged by means of a spring-locking device 79 with the resultthat the chain conveyor 5 is conveyed precisely in a forward direction.In the illustrated embodiment, this spring-locking device 79 comprises aspacer block which may be introduced between the travelling nut 77 andthe housing 73 and is displaceable relative to the housing 73 by meansof a cylinder. In the position of rest illustrated by the solid lines,the spring arrangement 78 is functioning, while on lowering of thelocking block a rigid connection is provided between the travelling nut77 and the housing 73.

If both chain guiding stations 7 are constructed as shown in FIG. 6, thechain conveyor 5 may be moved selectively in or counter to the directionof progressive movement indicated by the arrow 22, with thespring-locking device 79 being selectively activated in the case of thechain wheel driving the chain conveyor 5 while, in the case of thenon-driven guide sprocket 71, the spring-locking device is disengaged inthe manner shown in FIG. 6.

FIGS. 6 and 7 further show that the guide rails 23 in the region of thechain guiding station 7 comprise a fixed guide rail portion 80 and amovable guide rail portion 81. The movable guide rail portion 81 issupported so as to be movable along guide columns 82 and may be securelyclamped on said guide columns. As shown more clearly in FIG. 6, theguide rail portions 81 are curved in the direction of arrow 22 and areat a distance 83 from the drive shaft 72 and the axis of rotation of theguide sprocket 71 which is greater than a radius 84 of a root circle ofthe guide sprocket 71. In the region of the zenith of the guide sprocket71 facing the guide rails 23, this distance 83 decreases to the radius84 in a quadrant following this zenith in a clockwise direction.

The possibility of displacement along the guide columns 82 is necessarybecause the run-in ratios between the chain links formed by theworkpiece carriers 3, in particular the track rollers 33 disposed on thechain link pin 34 and the tooth spaces 85 of the guide sprocket 71 varyas a result of the displacement of the drive shaft 72 for tensioning thechain conveyor 5. Guidance of the track rollers 33 in the region oftransition to the guide sprocket 71 is therefore required in order tocompensate the varying chain speeds arising from the polygonal effect.These occur primarily in installations according to the inventionbecause of the fact that the length of the individual chain links--sincethese act as workpiece carriers 3--is relatively great and for spatialreasons the guide sprocket 71 cannot be constructed with a diameterlarge enough for it to comprise at least sixteen teeth. But it is onlyfrom a tooth number of sixteen teeth upwards that the degree ofirregularity virtually no longer manifests itself.

A further advantage of the solution according to the invention lies inthe fact that two track rollers 33 disposed parallel to one another areassociated with each guide rail 23. In the chain guiding station 7, awidth 86 of the guide rail portion 81 is therefore smaller than a width87--FIG. 4--of a track roller 33. The second track roller 33 associatedwith the same guide rail 23 is associated with the guide rail portion 80which, in the region of intersection with the guide rail portion 81,similarly has a width corresponding to the width 86. In each case,therefore, the guide sprocket 71 associated with one of the two guiderails 23 is disposed in alignment with the guide rail portion 80. Theuse of two track rollers 33 therefore makes it possible to compensatethe varying relative speeds during running-in of the track rollers 33 intooth spaces 85. Whereas the track roller 33 rolling on the guide railportion 81 rolls off according to the forward movement of the chainconveyor 5, when the second track roller 33 meshes in the tooth space 85this produces an additional relative movement dictated by an additionalradial relative movement between the guide sprocket 71 and the trackroller 33 or the workpiece carrier 3. If, instead of two track rollers33 associated with each guide rail 23, there were only one, slidingfriction would occur either between the tooth space and this trackroller or between the guide rail portion 81 and the track rollerassociated therewith. This can be avoided by disposing two independentlymovable track rollers adjacent to one another.

FIG. 8 shows the allocation of the individual track rollers 33 to theguide rail portions 80 and 81 in the region of the chain guiding station7.

This figure further shows that, as a result of the disposition of thetrack rollers 33, more details of which are given in FIGS. 9 and 10, theworkpiece carriers 3 are conveyed also during the return run in theguideway 12 by means of the track rollers 33. There is consequently nosliding friction either between the workpiece carrier 3 and the guideway12 when the workpiece carrier are conveyed back along the return course.This prevents excessive wear of these parts and makes it possible to getby with a low expenditure of energy.

A workpiece carrier 3 serving as a chain link is shown on an enlargedscale in FIGS. 9 and 10. The workpiece carrier comprises a basic elementwhich is provided in its central region with an opening 89. This opening89 allows the component to be processed also from the underside of theguideway 11. Bores 90 and threaded bores 91 are also disposed in thebasic element 88 for accommodating a carrier plate or assembly plateused to hold and position parts for assembly or the finished component.

The lateral guide rail 54 is fastened on the side surface 30 by means ofcountersunk screws 92, of which one is shown. In an end region facingthe workpiece carrier 3 downstream in feed direction--arrow 22, thebasic element 88 has the coupling extension 38 which is penetrated bythe chain link pin 34. The chain link pin 34 bearing the track rollers33 is held in its lateral position by the lateral guide rail 54. Arecess 93 is also provided in the region of one of the two track rollers33 so that the latter projects on the side remote from the guide rail 23over a guide shoulder 94. A side wall 95 of this guide shoulder 94 isused for lateral guidance of the workpiece carriers 3 in the returncourse in the region of the guideway 12, this being shown more clearlyin FIGS. 4 and 8. This allows the entire region of the basic element 88located between the side walls 95 to extend between the guide rails 39and the guide surfaces 40 of the guideway 12 and allows any parts orcomponents still located on its surface to drop freely downwards in thereturn course, this especially avoiding the risk of their becomingjammed between the guide rails or surfaces 39, 40 and the workpiececarriers 3.

The feed drive 6 may take the form of any drive arrangement. Thus, it ispossible to use electric angular stepping motors or other types ofstepping motors or alternatively mechanically limited drive motors. Itis also possible to use suitable pneumatic or hydraulic drives withservo controls. Speed regulation may be effected in such a way that thedrive is not acted upon abruptly by the full feed speed, with the speedinstead rising increasingly over an acceleration curve in order then,before the end of feed, to decrease in a deceleration phase to zero. Itis thereby possible to prevent any parts lying loose on the chain linksor workpiece carriers 3 from being flung off.

As FIG. 10 further shows, it is possible for the pressure rollers 29 tobe disposed spaced apart in feed direction--arrow 22--by twice thedistance of the support rollers 28, in which case they are each locatedcentrally between two adjacent opposing support rollers 28. It ismoreover also possible for the pressure rollers 29 and the supportrollers 28 to be disposed uniformly spaced apart in feeddirection--arrow 22--but offset relative to one another by half theirdistance apart, as is shown by an additional pressure roller 29indicated by broken lines. Another alternative is however for thepressure rollers 29 to be disposed directly opposite the support rollers28, this being diagrammatically illustrated by pressure rollers 29indicated by dash-dot lines. Here it may prove advantageous if thepressure rollers 29 indicated by the solid lines exert a higher pressureforce towards the opposing support rollers 28 than the pressure rollers29 indicated by the broken lines. It can thereby easily be ensured thatin the workstation the workpiece carrier 3 is positioned in athree-point grip between two support rollers 28 and the pressure roller29 disposed centrally therebetween. The pressure rollers 29 indicated bythe broken lines then only prevent pitching of the workpiece carriers 3or canting of the chain conveyor 5 during forward movement of the chain.

For adjustment of the chain conveyor and resetting of the feed drive,the housing 73 is penetrated by a bore which extends parallel to thedrive shaft 72 and into which a centering pin 96 can be inserted whenbores disposed in the guide sprocket 71 are in a corresponding position.After insertion of the centering pin 96, by means of which an exactposition of the chain relative to the guide sprocket 71 or the housingpart 8 is fixed, it is possible, for example, for a rotary transducerfor an angular stepping motor to be set to zero so that the workpiececarriers 3 are halted by the feed movement in the subsequent cycleoperation always at the exact same point along the housing parts 8.

It is also possible for the lateral guideways 24 and 25 to be formed byguide rails which cooperate with guide rollers disposed in the workpiececarrier 3 It is then possible, for example, to preload the stop railforming the lateral guideway 24 under spring initial tension in thedirection of the lateral guideway 25 with the result that, in this casetoo, play-free guidance of the workpiece carriers 3 along the lateralguideway 25 can be achieved On the other hand, it is also possible tmake the guide rollers disposed between the guide rail of the lateralguideway 24 and the workpiece carrier 3 from a radially resilientmaterial so that the clamping force in the direction of the lateralguideway 25 is provided by these rollers.

Naturally, it is also possible for the damping device to be formed byrubber spring blocks, pneumatic springs or means other than a helicalspring. The setting device may also be formed by pneumatic or hydraulicdrive mechanisms, in which case the damping device may also beincorporated in these.

I claim:
 1. An installation for processing and/or assembling components,which comprises(a) a housing unit including(1) a plurality of adjacenthousing parts of identical construction, (2) chain conveyor guidingstations at respective ends of the housing unit and (3) coupling devicesfor interconnecting the housing parts and guiding stations in alignmentwith each other, (b) support devices for supporting the housing unit ona support surface, (c) a driven chain conveyor comprised of workpiececarriers forming chain links of the chain conveyor, each workpiececarrier being equipped with receptacles for the components, and (d) aguidance device for the chain conveyor, the guidance devicecomprising(1) guide rails for the chain conveyor, the guide railsextending parallel to an upper side of the housing parts along thehousing unit for vertically guiding the workpiece carriers, and (2)guideways extending parallel to the guide rails on the upper side of thehousing parts for laterally guiding the workpiece carriers, theguideways comprising rollers spaced apart from one another along theguideways, the rollers being supported for rotation on axes extendingsubstantially perpendicularly to the upper sides of the housing parts.2. The installation of claim 1, wherein the guide rails on the upperside of the housing parts vertically guide the workpiece carriers in anupper course of the chain conveyor, and further comprising guide railsat a lower side of the housing parts for vertically guiding theworkpiece carriers in a lower course of the chain conveyor, the guidingstations guiding the chain conveyor between the upper and lower chaincourses.
 3. The installation of claim 1, wherein the housing parts andguiding stations have facing end plates, and the coupling devicesinterconnect the end plates.
 4. The installation of claim 1, wherein therollers at one longitudinal side of the chain conveyor are rigid whilethe rollers at an opposite longitudinal side of the chain conveyor exerta pressure on the workpiece carriers to press the workpiece carriersagainst the rigid rollers.
 5. The installation of claim 4, wherein therollers at the opposite longitudinal side of the chain conveyor areradially resilient pressure rollers, the distance between the unstressedpressure rollers and the opposite rigid rollers being smaller than thewidth of the workpiece carriers.
 6. The installation of claim 4, whereinthe rigid and pressure rollers are offset from each other in thelongitudinal direction of the chain conveyor.
 7. The installation ofclaim 1, further comprising a table board displaceably supported on eachhousing part for supporting processing and assemblying devices.
 8. Theinstallation of claim 7, wherein the guide rails on the upper side ofthe housing parts vertically guide the workpiece carriers in an uppercourse of the chain conveyor, and further comprising guide rails at alower side of the housing parts for vertically guiding the workpiececarriers in a lower course of the chain conveyor, the guiding stationsguiding the chain conveyor between the upper and lower chain courses,the housing defining a clearance between the upper and lower guiderails, the table board being mounted in said clearance and having alength extending in the direction of the guidance device which issmaller than the length of the clearance in said direction.
 9. Theinstallation of claim 8, further comprising support rails for the tableboard for displaceably mounting the table board in said clearance. 10.The installation of claim 1, comprising a guide sprocket for the chainconveyor disposed in each chain conveyor guiding station, and a feeddrive for the chain conveyor connected to the guide sprocket in at leastone of the guiding stations for driving the chain conveyor.
 11. Theinstallation of claim 10, further comprising a damping device connectedto the guide sprocket, the damping device including a spring extendingin the longitudinal direction of the chain conveyor.
 12. Theinstallation of claim 11, further comprising a spring-locking deviceassociated with the spring.
 13. The installation of claim 10, furthercomprising a setting device connected to the guide sprocket, the settingdevice including a threaded spindle extending in the longitudinaldirection of the chain conveyor.
 14. The installation of claim 1,wherein each housing part has a length corresponding to a multiple ofthe length of the workpiece carriers.
 15. The installation of claim 1,wherein the support devices are L-shaped supports disposed at sidesurfaces of the housing parts, the support having a shorter leg adjacentthe support surface and a longer leg adjacent the side surfaces of thehousing parts.
 16. The installation of claim 15, wherein the L-shapedsupports are disposed in a mirror-inverted manner at opposite ones ofthe side surfaces in a common plane extending transversely to theconveyor chain.
 17. The installation of claim 1, wherein the housingparts have mounting rails at side surfaces thereof and the supportingdevices are fastened on the mounting rails.
 18. An installation forprocessing and/or assembling components, which comprises(a) a housingunit including(1) a plurality of adjacent housing parts of identicalconstruction, (2) downstream and upstream chain conveyor guidingstations at respective ends of the housing unit, a guide sprocket beingdisposed in each guiding station and having an axis of rotation, and (3)coupling devices for interconnecting the housing parts and guidingstations in alignment with each other, (b) support devices forsupporting the housing unit on a support surface, (c) a driven chainconveyor trained over the guide sprockets and comprised of workpiececarriers forming chain links of the chain conveyor, each workpiececarrier being equipped with receptacles for the components, and (d) aguidance device for the chain conveyor, the guidance devicecomprising(1) guide rails for the chain conveyor, the guide railsextending parallel to an upper side of the housing parts along thehousing unit and having portions extending from a respective housingpart adjacent the guiding station at each end into the guiding stationsubstantially as far as the axis of the guide sprocket for verticallyguiding the workpiece carriers, the guide sprocket defining a rootcircle of revolution and having a zenith, and the guide rails in theguiding station being spaced at the zenith a distance from the guidesprocket axis which is greater than the radius of the root circle andsaid distance decreasing in a peripheral direction of the guide sprocketto the radius of the root circle.
 19. The installation of claim 18,wherein the guide rail portions are repositionable, and furthercomprising a longitudinal repositioning device displaceably mounted on aguide column in the guiding station.
 20. The installation of claim 19,wherein the guide rail portions are comprised of two sections which aretelescopically displaceable relative to each other.
 21. The installationof claim 18, further comprising spaced apart track rollers supportingthe conveyor chain on the guide rails, the track rollers meshing withthe sprocket guides and having a width which is smaller than the widthof the guide rail portions.